The purpose of the Cellular and Animal Modeling Core is to provide both tissues and tissue processing and a facility for the development of novel epithelial cell lines from the intestinal tissues of transgenic mice. The focus of the core's efforts will be on intestinal diseases with the intent to improve human health through advances in prevention, diagnosis, or prevention of digestive diseases. The core has two components: the Novel Cell Line Development Subcore and the Tissue Morphology Subcore. The Novel Cell Line Development Subcore provides a unique service in developing conditionally immortalized epithelial cell lines from the different segments of the gastrointestinal tract of transgenic mice with gene deletions known to be associated with known gastrointestinal pathologies. One of the major impediments in gastrointestinal research has been the lack of normal epithelial cell lines derived from intestinal mucosa. This subcore addresses this lack by utilizing a novel transgenic mouse, the "Immortomouse," which carries a temperature-sensitive mutant of the SV40 large T gene, which is an immortalizing gene. The temperature-sensitive form of this gene is only active at the permissive temperature (33C) and is inactivated by incubation at 39C. This means that primary cells isolated from the intestinal epithelium can be immortalized by incubation at the permissive temperature but then reverted to a normal phenotype by increasing the incubation temperature to 39C. The introduction of this immortalizing gene into the transgenic mouse of interest is achieved by mating a transgenic mouse with the Immortomouse. After two rounds of mating, mice homozygous for the transgene or knockout phenotype and carrying the immortalizing gene are obtained. Tissues from these animals can then be cultured using techniques published by the core director. To date these methods have been successfully used to develop 50 epithelial cell lines from different gastrointestinal tissues, including stomach, small intestine, colon, pancreas, and liver from 10 different transgenic mice. The Tissue Morphology Subcore provides services for the acquisition of human intestinal tissue and for the histologic processing of both human and animal intestinal tissue. In addition, Dr. Washington, the core Director, provides the necessary expertise for interpretation of the histologic findings obtained in these studies. The availability of a central service such as this with all specimens being processed by one highly skilled histology technician enhances the findings from the other cores, as it provides a level of consistency in the interpretation of histologic changes found in the animal models being used by members of the VDDRC. In addition, this subcore provides a supply of high quality, rapidly processed human specimens as required by the VDDRC investigators.